Heat Controller VMH18SC-1, VMH12SC-1, VMH24SC-1 High evaporator coil temp.T2 protection, Auto-mode

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Running mode
Cooling
Fan-only
Heating

Heat Controller, Inc.

VMH Series

Service Manual

 

 

 

8.4.3.5 High evaporator coil temp.T2 protection:

(1) T2>TEH2 compressor running frequency decreases to the lower level every 20s. If the frequency decreased to F2 and the T2 still over TEH2 for 3 minutes, the compressor will stop. If T2 deceased to lower than 118°F/48°C, or 118°F/48°C <T2< TEH2 last for 6 minutes, release the frequency limit control.

Unit

°F TEH2 (°C)

9K/12K

127°F

53°C

18K /24K

131°F

55°C

(2) If T2>140°F/0°C, the compressor stops and restarts when T2<118°F/48°C

8.4.4 Auto-mode

This mode can be selected by the remote control and the set temperature can be changed between 17~86°F/62°C.

In auto mode, the machine will select cooling, heating or fan-only mode according to the difference between T1 and Ts.

T1-Ts

T1-Ts1°F

-1< T1-Ts ≤1°F

T1-Ts ≤-1°F

Indoor fan will run in auto fan of the relevant mode.

The louver operates the same as in relevant mode.

If the machine switches mode between heating and cooling, the compressor will stop for 15 minutes and then choose mode according to T1-Ts again.

If the set temperature is modified, the unit will choose run function again.

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Contents Inverter Single Zone Ductless Mini Split Heat Pump Contents Safety Precaution Precaution Installation  For installation, always contact the dealer  Caution  Do not block the inlet or outlet of air flow  Keep level even when installing the product Operational  Use two or more people to lift and transport the product Do not drink the water drained from the product Anti-freeze protection in cooling FunctionOutdoor unit Compressor delay Indoor Unit DimensionOutdoor Unit Model Dimension mmIndoor Outdoor Refrigerant Cycle DiagramWiring Diagrams VMH09SC-1 A-VMH12SC-1 VMH18SC-1 Installation details Single Zone V Series Inverter System Pipe length and the elevationSystem Evacuation and Charging Pressure Test & EvacuationOperation characteristics Abbreviation Electronic functionDisplay function Main Protection Preheat termination Preheat modeFan only mode Operation Modes and FunctionsCooling Mode Compressor running rules Model Current Frequency decreases HoldsOutdoor fan rules Condenser high temperature T3 protectionIndoor fan running rules Heating Mode Compressor running rules Evaporator low temperature T2 protectionT1-Ts-ΔT +5.0 +4.5 +3.5 +3.0 +2.5 +2.0 +1.5 +1.0 +0.5 Outdoor fan running rules I1HEAT I2HEAT I3HEATVMH18SC-1 Indoor fan rulesUnit TEL0 TEL1 VMH09SC-1 VMH12SC-1Defrost mode: Defrost Actions For 9K and 12K unit For 18K and 24K unit Auto-mode High evaporator coil temp.T2 protectionForced operation function Dehumidify modeSleep function mode Timer functionAuto-Restart function Ionizer Clean Air functionAutomatic front panel function Safety TroubleshootingDiagnosis and Solution Indoor Unit Error DisplayEeprom parameter error diagnosis and solution VMH Series E3 Indoor or E7 Outdoor Igbt over current protection diagnosis and solution VMH Series Inverter compressor drive error diagnosis and solution 29 P3 Error Low Ambient ProtectionPosition Resistance Value Key parts checkingVMH Series Some frequently-used R-T data for T1, T2, T3 and T4 sensor 2012